package Usb_Usage;public class Computer {    void UseUsb(Usb usb)    {        usb.Start();        if(usb instanceof Mouse)        {            Mouse mouse = (Mouse) usb;            mouse.Click();        }else if(usb instanceof KeyBoard)        {            KeyBoard keyBoard = (KeyBoard) usb;            keyBoard.Knock();        }        usb.Over();    }}